Sirius & Orion share a single Warframe slot but carry two full ability kits, which makes building for them feel busy at first. Seven abilities across the pair sound complicated, yet the strongest play is simple. You stack Ability Strength, feed the Constellation meter with cheap casts, then unleash Celestial Clash. Once the muscle memory clicks, the duo one-shots high-level Steel Path enemies in a wide area.
Quick answer: Make Sirius your frontman and subsume Roar over Coronal Ejection (Sirius 1). Stack Ability Strength on Sirius, push Efficiency and Strength on Orion, fill the Constellation meter with Orion’s cheap abilities, then switch back to Sirius and cast Celestial Clash. The ult uses the stats of whichever brother starts it, so always open it with the high-Strength Sirius.
How Celestial Clash works (and why Strength matters)
Celestial Clash is the shared ultimate. Both brothers take to the skies and trade strikes, and each strike spends one Constellation Star to deal Blast damage in a wide radius. A fully stacked meter gives you seven strikes. Every successful strike adds +55% additive Critical Chance, so after two or three hits you start deleting tough targets, and a full chain reaches +330% Critical Chance on the final blow.
Three mechanics decide how the ult performs, and they are easy to miss in the heat of a mission.
- The ult inherits the stats of whichever brother begins it. Open it with your high-Strength Sirius for the biggest damage.
- The Constellation meter fills left to right while you cast abilities, but Celestial Clash spends those Stars right to left.
- The brother who lands the final strike also scoops up every pickup gathered during the ult, including Energy Orbs. End on Sirius to keep his energy topped up.
You generate Stars by casting abilities, and you cannot add more than two Stars of the same color in a row. Match a Star’s color to the attacking brother’s color during the ult to gain the bonus Critical Chance, which is why a fixed cast order matters.
Sirius & Orion ability list
| Slot | Sirius | Orion |
|---|---|---|
| 1 | Coronal Ejection — throws a Jade Light scythe for Heat damage and grabs pickups in its path. | Gravitic Slash — wide Slash strike that repels enemies and strips shields and armor. |
| 2 | Jade Stars — conjures Jade Light motes that launch on attack for Heat damage and status. | Astral Shell — wraps Orion in a shell that becomes a decoy when hit. |
| 3 | Light’s Sanctuary — a growing well of light that heals, revives, and reduces incoming damage. | Event Horizon — a drifting black hole that traps enemies in a large radius. |
| 4 | Celestial Clash — the shared ultimate; each strike spends a Constellation Star for Blast damage and matched-color strikes grant Critical Chance. | |
The passive is worth noting because it smooths the energy cost of swapping. Switching between Sirius & Orion grants 45% Ability Efficiency for the next two casts, so tagging often is cheaper than it looks.
Sirius mod and Arcane setup (frontman)
Sirius is the damage half. The goal here is high Ability Strength while staying tanky enough to hold position during the combo. With this layout you only need to invest one Forma on Sirius for an Adaptation slot, and the build reaches around 278% Strength before Molt Augmented and Archon Shards.
| Slot | Mod |
|---|---|
| Aura | Corrosive Projection (or Brief Respite with an extra Forma) |
| Exilus | Empty, or Power Drift if you add Forma |
| V polarity | Blind Rage |
| D polarity | Primed Redirection |
| Omni polarity | Primed Flow |
| Forma D polarity | Adaptation |
| Standard | Transient Fortitude |
| Standard | Stretch |
| Standard | Precision Intensify |
| Standard | Streamline |
| Arcane 1 | Arcane Energize |
| Arcane 2 | Molt Augmented (or Arcane Aegis for more tankiness) |
The survivability comes from a large Shield pool, 90% damage reduction from Adaptation, and up to 75% reduction from a maxed Light’s Sanctuary. That baseline is comfortable enough that you can plant Sirius and play him as a weapons platform with support on the side if you want.
Orion mod and Arcane setup (wingman)
Orion’s job is cheap, fast casting to fill the Constellation meter and to drop a very wide Event Horizon that pulls in multiple rooms of enemies. Because the ult borrows Sirius’s stats, Orion can lean into Efficiency and Range instead of raw Strength. This layout needs no Forma.
| Slot | Mod |
|---|---|
| Aura | Energy Siphon (or Power Donation with one extra Forma) |
| Exilus | Empty |
| V polarity | Primed Continuity |
| D polarity | Primed Redirection |
| Omni polarity | Overextended |
| Standard | Stretch |
| Standard | Augur Reach |
| Standard | Energy Nexus |
| Standard | Boreal’s Hatred |
| Standard | Fleeting Expertise |
| Arcane 1 | Arcane Energize |
| Arcane 2 | Arcane Aegis |
Running Arcane Energize on both brothers is intentional. The bonus energy proc stacks across the pair, so each one can trigger a 125 energy refund and effectively refill the other. That keeps the whole duo’s energy economy easy to sustain.
Helminth, Archon Shards, and companion
Subsume Roar in place of Coronal Ejection (Sirius 1). Sirius must be the frontman when you infuse it, but you can swap which brother leads at any time afterward regardless of what you picked during the Jade Shadows choice. Roar’s damage multiplier is what pushes Celestial Clash over the top.
Both Warframes share Archon Shard bonuses, so plan them as one set.
- One Tauforged yellow Shard (or two normal yellow Shards) for Cast Speed. The duo casts constantly, so this matters.
- Two red Shards, Tauforged or normal, for Ability Strength.
- Remaining slots are flexible. Adding more Cast Speed and Strength is the simplest way to round it out.
For a companion, Dethcube (regular or Prime) with the Energy Generator precept adds another safety net for energy. Pair it with Contagious Bond to spread status and Vaporize for cleanup.
Celestial Clash ability rotation
This rotation builds a full seven-Star meter and always leaves you on Sirius for the ult. Set your abilities to invert tap and hold if you prefer the swap on hold, then follow the sequence.
You will know it worked when the strike counter shows colossal Blast damage across the trapped group and the final hit lands with the stacked Critical Chance. If the ult feels weak, the usual cause is starting Celestial Clash on Orion instead of Sirius, since the ult then uses Orion’s lower Strength. A mismatched color order also costs you the bonus Critical Chance on those strikes.
You will not always need the perfect seven-Star, +330% chain. Once the rhythm is familiar you can shorten the combo or improvise based on the room. The kit stays flexible, so it pays to keep weapons that cover the gaps, such as a Viral and Corrosive primer plus a strong single-target gun for modes like Disruption.
